KR20020071894A - Optical recording medium - Google Patents

Abstract

A recording layer comprising an organic dye capable of absorbing laser light directly or via another layer on a transparent support substrate having pregrooves and prepits, and an optical recording medium having a metal reflecting layer, wherein the organic dye is reproduced. Refractive index nk at wavelength λ _{2 is} at least 2.2; For the depth of pre-grooves and pre-pits on the substrate in the playback wavelength λ ₂ λ _4/4 or more and; Again, the following formula:

0.25r ≦ wg ≦ 0.38r;

0.25 ≦ wp / wg ≦ 0.75;

θgr ≦ θpr; And

θpr ≤θpt

[Wherein r is the diameter of the recording laser beam represented by λ ₁ / NA, where λ ₁ is the recording wavelength [µm] and NA is the numerical aperture of the objective lens); wg [μm] is the half width of the pregroove and [theta] gr is the cross-sectional inclination angle of the pregroove in the substrate radius direction; wp [μm] is a half width in the substrate radial direction of the prepit, θpr is the cross-sectional inclination angle of the prepit in the substrate radius direction, and θpt is the cross-sectional inclination angle in the tangent direction of the prepit. Optical record carrier.

Description

Optical recording medium {OPTICAL RECORDING MEDIUM}

Among the disc media for optical recording, recordable compact discs capable of recording only once are generally used widely because they are compatible with normal read-only CD-ROMs. In addition, development of recordable media has been advanced for DVDs (Digital Versatile Disks) having a higher recording density than CDs. Among them, the recordable DVDRs are highly compatible with DVD-ROMs. In these recordable media, organic pigments are used in the recording layer, and the pigments irradiated with the laser light are locally heated to cause chemical and / or physical changes such as decomposition, deformation, vaporization, melting and solidification, thereby causing pits to be reduced. It is possible to record information.

On the other hand, there is also proposed an optical recording medium in which a read-only area (ROM area) such as the CD-ROM or DVD-ROM and a recording area or recordable area (R area) such as the CDR or DVDR are combined in the same disc. This specification will become very important in the future. Such a disk is called a "hybrid disk", and a prepit is formed on a substrate in a ROM region, and a pregroove is formed in an R region.

In recent years, especially in consumer use, the development from CD to DVD has been steadily progressing, and in the process, the importance of copyright protection for music, video and moving picture software has been emphasized. Therefore, in particular, thorough copy protection is inevitable, especially for DVDR media which are allowed to record in the same format. For this reason, it is standardized to have the management data for copy protection in advance as a ROM area in the data management area on the disk. That is, in the future, all DVDRs sold in the consumer market must be supplied as a hybrid type, and a proposal for a hybrid DVDR as simple and stable as possible has been demanded.

Conventionally, hybrid discs using an organic dye as a recording film have been standardized in CDRs, but acquisition of signal amplitude (recording modulation degree) in the ROM area is more difficult than in the R area, and sufficient characteristics are not obtained. This is because a recording layer containing a dye is formed not only in the pregroove image of the R region but also in the prepit image of the ROM region, so that an appropriate modulation degree cannot be given to the same prepit shape as commercially available CDs.

For this reason, Japanese Unexamined Patent Application Publication No. 4-146537, Japanese Unexamined Patent Application Publication No. 9-120586, etc., control the optical path length difference by varying the depth of prepit and pregroove to obtain a good signal balance. It is disclosed that it can be done. However, this technique has a drawback that it is difficult to manufacture because it requires stamping of two beams normally, and that the recording signal quality is concerned because the groove shape designed relatively shallowly becomes V-shaped.

In addition, a method of controlling the deposition position of the recording layer to form the recording layer only in the R area and the direct reflection layer in the ROM area has been proposed, but the boundary from the R area to the ROM area or from the ROM area to the R area is also proposed. It is difficult to control, and in view of the compatibility of playback with a CD or DVD player, a practical solution cannot be achieved.

In addition, in most cases, a temporary prescription for disposing a small number of products by producing a prepit by recording with a writer in advance in a predetermined area of a recordable disc having only an ordinary R area is employed. However, of course, this prescription is not applicable to mass production.

Therefore, in the ROM area of the hybrid disc, it is preferable to form prepit information from a stamper disk by an appropriate method such as injection molding.

The present invention relates to an optical recording medium capable of recording and / or reproducing information by using laser light. In particular, the present invention is a recordable type (ie, write-once type) recording medium capable of recording at a higher density than a CD, and pre-pit and pre-groove on a substrate in advance. A hybrid type high density optical recording medium comprising a.

1 (a) is a diagram showing a cross-sectional shape in the radial direction of the pregroove of the R region; Fig. 1 (b) is a diagram showing a cross-sectional shape in the radial direction of the prepit of the ROM area; Fig. 1 (c) is a schematic diagram showing a cross-sectional shape in the tangent direction of the prepit.

<Explanation of symbols in the drawings>

1: Substrate 2: Pregroove

3: prepit d: depth

wg: Half width of pregroove [theta] gr: Radial cross-sectional inclination angle of the pregroove

wp: Half width of prepit θpr: Radial cross-sectional inclination angle of prepit

θpt: Cross section inclination of tangent of prepit

Disclosure of the Invention

An object of the present invention is to provide a hybrid optical recording medium in which at least a recording layer containing a dye and a reflective layer are provided in this order on a substrate formed of a ROM region having a prepit and an R region having a pregroove. The present invention provides an optical recording medium that exhibits good recording and reproducing characteristics such that both the ROM area and the R area satisfy the DVD standard.

When the present inventors, as a result of intensive studies to solve the above problem, the beam spot size than DVDR medium requires the formation of small, high-density recording pits and a depth λ _4/4 or more, pre-pits and pre-grooves have the same depth Subsequently, it has been found that the control of the half width of the prepit and the pregroove and the inclination angle, in particular, the prepit, give the inclination angle in the tangent direction to obtain a good signal from the ROM region. Further, by defining the refractive index of the dyeing material used for the recording film, it was found that better characteristics were achieved and the present invention was completed.

That is, the present invention,

1. An optical recording medium having a metal reflective layer and a recording layer comprising an organic dye capable of absorbing laser light directly or via another layer on a transparent support substrate having pregrooves and prepits. The refractive index nk at the reproducing wavelength λ ₂ is 2.2 or more; For the depth of pre-grooves and pre-pits on the substrate in the playback wavelength λ ₂ λ _4/4 or more and; Again, the following formula:

0.25r ≦ wg ≦ 0.38r;

0.25 ≦ wp / wg ≦ 0.75;

θgr ≦ θpr; And

θpr ≤θpt

[Wherein r is the diameter of the recording laser beam represented by [lambda] ₁ / NA, where [lambda] ₁ is the recording wavelength [[mu] m], NA represents the numerical aperture of the objective lens); wg [μm] is the half width of the pregroove and [theta] gr is the cross-sectional inclination angle of the pregroove in the substrate radius direction; wp [μm] is a half width in the substrate radial direction of the prepit, θpr is the cross-sectional inclination angle of the prepit in the substrate radius direction, and θpt is the cross-sectional inclination angle in the tangent direction of the prepit. Optical record carrier.

2. The recordable optical recording medium according to item 1, wherein the pregroove and the prepit formed on the substrate satisfy a relationship in which θgr <

3. The recordable optical recording medium according to the above 1 or 2, wherein the pregroove and the prepit have the same depth.

4. The recordable light according to any one of items 1 to 3, wherein a recording layer containing an organic dye is formed on the prepit or the pregroove with a film thickness in the range of 50 m to 150 nm. Record carrier.

5. The recordable optical recording medium according to any one of items 1 to 4, wherein the dye contained in the recording layer is an organic dye containing at least one pyrrole unit or a metal complex thereof.

6. The pigment | dye contained in the said recording layer has following formula (1):

(Wherein, R1 to R13 are each independently a hydrogen atom, a halogen atom, C ₁ to substituted or unsubstituted alkyl group of C _12, C ₁ to alkoxy substituted or unsubstituted of C ₁₂ group or a C ₆ to C ₂₀ The substituted or unsubstituted aryl group; M is a pyrromethene-metal complex represented by the above), wherein the recordable optical recording medium according to 5 above.

7. The recordable optical recording medium according to any one of items 1 to 6, wherein lambda ₁ is 0.63 µm to 0.66 µm and NA is 0.60 ± 0.1.

8. The recordable optical recording medium according to any one of items 1 to 7, wherein the recording layer, a reflective layer, an adhesive layer via direct or other layers, and another substrate are laminated on a transparent substrate. .

Best Mode for Carrying Out the Invention

The optical recording medium of the present invention includes, for example, a dye-containing recording layer, a reflective layer and a protective layer on a substrate on which a ROM region made of prepit and an R region made of pregroove having the same depth as the prepit are formed. The layer has the structure formed in this order, and the protective layer has the structure which laminated | stacked the dummy board | substrate through an adhesive material. The prepit of the ROM area and the pregroove of the R area have a specific shape.

With reference to FIG. 1, the shape of the prepit of ROM area | region and the shape of the pregroove of R area | region is demonstrated.

First, both the pre-pit (3) of the pre-groove (2), ROM areas of the R region formed in the substrate (1), depth (d) is, λ _2/4 to λ ₂ / of the third region (λ ₂ is reproducing wavelength Is preferred). For example, since the reproduction wavelength of DVDR is 650 nm, it is preferable to form both depths in the range of 162.5 nm-216.7 nm. If the depth is lower than the above range, the prepit signal amplitude of the ROM area is difficult to be obtained regardless of their shape, while if the depth is larger than the above range, substrate shaping is extremely difficult and not practical.

Next, the half width wg (the width of the pregroove at a depth of 1/2 of the depth of the pregroove) of the pregroove 2 of the R region shown in Fig. 1A is defined as λ ₁ / NA. It can be optimized depending on the type of the organic dye contained in the recording layer and the film formation method in the range of wg / r = 0.25 to 0.38 in the ratio with the beam spot size r. For example, when the reproduction wavelength λ ₁ of the DVDR is 650 nm (0.65 μm) and the numerical aperture NA of the objective lens is 0.65, the beam spot size r is about 1 μm, so the half width of the pregroove 2 is 0.25 to In this case, control of the following shape to the pregroove, that is, the shape (depth and width) of the reflective layer interface is equally important. If the half width of the pregroove half is less than 0.25, the leakage (crosstalk) of the signal through the land portion increases, which tends to deteriorate the signal quality (for example, jitter value). Conversely, when it exceeds 0.38, there arises a problem that the transferability at the time of substrate formation is significantly deteriorated, which is undesirable.

On the other hand, the half width wp of the prepit of the prepit of the ROM region shown in Fig. 1 (b) (the width of the prepit at the depth of 1/2 of the depth of the prepit) is wp / wg with respect to the pregroove described above. By being relatively narrow in the range of 0.25 to 0.75, it is possible to provide a signal modulation degree of finer pit, in particular, and it is easy to balance with the signal of the R region. If less than 0.25, the tracking output in the ROM area is extremely reduced. Further, when larger than 0.75, acquisition of signal modulation degree in the ROM area is insufficient. As the half width of the prepit, referring to the half width wg of the pregroove described above, it is in the range of 0.0625 to 0.285 µm, but may be appropriately selected so that the depth and the following inclination angle are compatible.

Moreover, in this invention, the cross-sectional shape of the said prepit is also prescribed | regulated. Particularly, the inclination angle of the pregroove is used to adjust the balance between the R area and the signal amplitude with respect to the radial pit cross-sectional inclination angle θpr and the track tangential direction (tangent direction) of pit cross-sectional inclination angle θpt (Fig. 1 (c)). As a result of preparing a substrate having a difference between Figs. Pr and? R, it is easy to obtain a modulation degree at? Pr? Also, the signal quality of the ROM region can be improved also with respect to the inclination angle of the prepit tangent. It is also possible to make the prepit and the pregroove at the same depth.

Here, as cross-sectional tilt angle (theta) gr of the pregroove 2, Preferably it is 45-65 degrees, More preferably, it is desirable that it is the range of 55-65 degrees. Further, as the cross-sectional inclination angle θpr in the substrate radial direction of the prepit 3, preferably, the relationship of the above θgr ≦ θpr is satisfied in a range of 55 to 75 °, more preferably 65 to 75 °. It is preferable to form. The cross-sectional inclination angle θpt of the prepit 3 in the tangent direction is preferably formed so as to satisfy the above relationship of θpr ≦ θpt in the range of 60 to 80 °, more preferably 65 to 80 °. desirable.

The pregroove and prepit shapes (width, depth and angle) can be controlled by the shape and irradiation intensity of the irradiator cutting beam during the exposure of strong laser power so as to irradiate the entire thickness direction of the photoresist film during stamper disc fabrication. Can be. To some extent, the angle and width can be adjusted depending on the molding conditions.

These pregrooves and prepits may be wobbling with optimized amplitude, respectively, or a landprep for address information may be formed separately between the wobbled pregrooves (land).

The shapes of these pregrooves and prepits can be measured by STM, AFM or SEM observation of frozen fracture surfaces.

In this invention, what is necessary is just to be transparent to the wavelength (lambda) ₂ of recording and reproduction light, and to have small optical anisotropy as a material of a board | substrate. For example, polymeric materials, such as a polycarbonate, a polyacrylate, a polymethacrylate, a polyolefin, an epoxy resin; It is possible to use inorganic materials such as glass and the like. In particular, a polycarbonate resin having a good balance of light transmittance and heat resistance and easy molding is preferable. Moreover, the polyolefin which has a ring skeleton is similarly preferable from a viewpoint that there is little optical anisotropy and low hygroscopicity.

The recording layer used in the present invention has a refractive index nk of 2.2 or more with respect to the reproduction wavelength λ ₂ , and the film thickness of the prepit or pregroove is formed in a range of 50 nm to 150 nm, so that the recording characteristics in the R region are satisfactorily achieved. It is preferable in view of ensuring sufficient reproduction output from the ROM area while maintaining it. If the refractive index is less than 2.2, it tends to be difficult to obtain the signal amplitude of the ROM region.

The film thickness of the recording layer outside the above range causes a significant deterioration of the recording quality.

Moreover, as a specific example of the pigment | dye used here, large cyclic aza-arylene pigment | dye, such as a phthalocyanine pigment | dye, a naphthalocyanine pigment | dye, and the aza porphyrin pigment | dye of 1-4 nitrogen of a meta position; Porphyrin-based pigments; Azo pigments; Indoaniline pigments; Azulenium pigments; Pyromethane dyes; Polymethine pigment | dyes, such as a cyanine pigment | dye, a merocyanine pigment | dye, and a squallium pigment | dye, etc. are mentioned. Among these, metal complex dyes containing at least one pyrrole unit are preferred as ones having good durability and good recording characteristics when high density recording is performed. In particular, as a dye having a high refractive index, the following formula (1):

(Wherein, R1 to R13 are each independently a hydrogen atom, a halogen atom, C ₁ to substituted or unsubstituted alkyl group of C _12, C ₁ to alkoxy substituted or unsubstituted of C ₁₂ group or a C ₆ to C ₂₀ Pyrromethene-metal complex dyes represented by substituted or unsubstituted aryl groups; M is a central metal are preferred.

Examples of the halogen atom represented by R1 to R13 include fluorine, chlorine, bromine and iodine atoms. As a substituted or unsubstituted alkyl group, a methyl group, an ethyl group, n-propyl group,

Isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group,

Isopentyl group, 2-methylbutyl group, 1-methylbutyl group, neopentyl group, 1,2-dimethylpropyl group,

1,1-dimethylpropyl group, cyclopentyl group, n-hexyl group, 4-methylpentyl group, 3-methylpentyl group,

2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group,

1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,2-dimethylbutyl group, 1,1-dimethylbutyl group,

2-ethylbutyl group, 1-ethylbutyl group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group,

1-ethyl-2-methylpropyl group, cyclohexyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl group,

4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group,

2,5-dimethylhexyl group, 2,5,5-trimethylpentyl group, 2,4-dimethylhexyl group,

2,2,4-trimethylpentyl group, 3,5,5-trimethylhexyl group, n-nonyl group, n-decyl group, 4-ethyloctyl group, 4-ethyl-4,5-dimethylhexyl group, n- Undecyl group, n-dodecyl group, methyl-4-butyloctyl group,

3,5-dimethylheptyl group, 2,6-dimethylheptyl group, 2,4-dimethylheptyl group,

2,2,5,5-tetramethylhexyl group, 1-cyclopentyl-2,2-dimethylpropyl group,

1-cyclohexyl-2,2-dimethylpropyl group etc. are mentioned. Examples of the substituted or unsubstituted aryl group of C ₆ to C ₂₀ include a phenyl group, a nitrophenyl group, a cyanophenyl group,

Hydroxyphenyl group, methylphenyl group, dimethylphenyl group, trimethylphenyl group, ethylphenyl group,

Diethylphenyl group, triethylphenyl group, n-propylphenyl group, di (n-propyl) phenyl group,

Tri (n-propyl) phenyl group, isopropylphenyl group, di (isopropyl) phenyl group,

Tri (isopropyl) phenyl group, n-butylphenyl group, di (n-butyl) phenyl group, tri (n-butyl) phenyl group,

Isobutylphenyl group, di (isobutyl) phenyl group, tri (isobutyl) phenyl group, sec-butylphenyl group,

Di (sec-butyl) phenyl group, tri (sec-butyl) phenyl group, t-butylphenyl group, di (t-butyl) phenyl group,

Tri (t-butyl) phenyl group, dimethyl-t-butylphenyl group, fluorophenyl group, chlorophenyl group,

Bromophenyl group, iodophenyl group, methoxyphenyl group, ethoxyphenyl group,

Trifluoromethylphenyl group, N, N-dimethylaminophenyl group, naphthyl group, nitronaphthyl group,

Cyanonaphthyl group, hydroxynaphthyl group, methylnaphthyl group, fluoronaphthyl group,

Chloronaphthyl group, bromonaphthyl group, iodonaphthyl group, methoxynaphthyl group,

Trifluoromethyl naphthyl group, N, N- dimethylamino naphthyl group, etc. are mentioned.

The central metal M is not particularly limited as long as it is a metal having the ability to form a complex with a dipyrromethene compound, but is selected from transition metals such as Ni, Co, Cu, Mn, Zn, and Pd from the stability and optical properties. It is preferable.

Of course, these pigment | dyes described above for the purpose of improving recording characteristics and / or durability may be mixed and used, or may be a mixture with one or more pigments other than the above. The recording layer may consist of two or more layers instead of a single layer.

The recording layer containing the dye may be deposited by an appropriate coating method such as spin coating, spray coating or roll coating. As for coating, a dye solution dissolved in a solvent that does not damage the substrate is prepared, and dried after coating. As a solvent to be used, Aliphatic or alicyclic hydrocarbon type, such as hexane, heptane, octane, methylcyclohexane; Aromatic hydrocarbons such as toluene and xylene; Ethers such as dibutyl ether and isopropyl ether; Alcohols such as ethanol, tetrafluoropropanol and methyl cellosolve; Halogen-based solvents such as chloroform and dichloromethane are appropriately selected and used. You may use these solvents individually or in mixture of 2 or more types.

In the case of stacking two or more recording layers, for application of the upper recording layer, it is preferable to select a solvent which does not damage the previously formed layer, for example, a solvent having a different polarity.

As a method of forming the recording layer, a vacuum deposition method may be used. This method is effective when the material constituting the recording layer is difficult to dissolve in the solvent or when a solvent which does not damage the substrate used cannot be selected, and in general, uniform film thickness control can be performed.

On the recording layer, a reflective layer using a metal such as Au, Ag, Pt, Cu, or an alloy thereof is formed. Especially Au which is stable to oxygen and moisture is preferable. The reflective layer may be deposited by vapor deposition, sputtering, ion plating, or the like. The film thickness of the reflective layer is 10 nm to 200 nm, preferably 50 nm to 150 nm. An intermediate layer may be formed between the metal reflection layer and the recording layer for the purpose of improving the adhesion and the reflectance between the layers.

A protective layer may be formed on the reflective layer. For example, the polymer may be formed of a polymer material such as polymerized by a general radical reaction (for example, acrylate or methacrylate), or polymerized by cationic polymerization with light such as epoxy. These resins may be polymerized alone or may be copolymerized with other monomers and / or oligomers. Especially, UV curable resin is preferable. The protective layer is formed by a spin coating method, a screen printing method, a bar coating method, or the like, but a spin coating method is often used from a working surface. Although these film thicknesses are used in the range of 1 micrometer-100 micrometers, 1-20 micrometers is preferable.

Hereinafter, the Example of this invention is shown. In addition, embodiment of this invention is not limited by this.

Examples 1-8 and Comparative Examples 1-8

The injection molded polycarbonate substrate having a spiral groove having a thickness of 0.6 mm and a pitch of 0.74 mu m having a diameter of 120 mm phi and a part of the lead-in area on the extension line of the pregroove has the following formulas (A) to (C):

A dye layer is formed from a 20 g / L ethylcyclohexane solution of any one pyromethene-based dye represented by a spin coating method, and 100 nm of Au reflection layer is deposited on the dye layer by sputtering, and further, a UV curable resin. After applying SD-17 (manufactured by Dainippon Inkki Co., Ltd.) and UV curing, a polycarbonate substrate having a thickness of 0.6 mm was superimposed on the resin layer in the same manner as described above, and a Z8412 (manufactured by JSR) radical adhesive was applied therebetween. An optical recording medium was produced.

The optical recording medium was used as a disc tester "DDU-1000" (pulsetech Co., Ltd.) using a DVD standard of prepit area at wavelength: 658 nm, NA: 0.60, and signal modulation degree (I14 / I14H) and pregroove area. The EFM signal was recorded at the same time, and the modulation degree (I14 / I14H) at that time and the jitter (clock to jitter) of the recording section were also evaluated.

The pigment | dye, the prepit and pregroove shape of the board | substrate and the signal evaluation result which were examined by the Example and the comparative example are shown in following Table 1. Here, the pregroove shape and the prepit shape of the substrate were measured based on AFM and SEM (cross-sectional shape) observation.

Pigmentation Board shape Signal characteristic Pigment Refractive index (%) Thickness (nm) d (nm) wg (μm) wp (μm) wg / r wp / wg θgr (°) θpr (°) θpt (°) R area ROM area Jitter (%) Modulation Modulation Example 1 A 2.62 100 175 0.35 0.20 0.32 0.57 60 70 72 7.5 0.68 0.65 Example 2 A 2.62 100 175 0.35 0.25 0.32 0.71 60 70 72 7.5 0.68 0.60 Example 3 A 2.62 100 175 0.35 0.25 0.32 0.71 55 68 68 7.9 0.66 0.60 Example 4 A 2.62 100 175 0.38 0.15 0.35 0.39 60 70 72 7.4 0.65 0.72 Example 5 A 2.62 60 175 0.38 0.15 0.35 0.39 60 70 72 8.5 0.60 0.72 Example 6 A 2.62 140 190 0.38 0.15 0.35 0.39 60 66 68 7.9 0.75 0.65 Example 7 A 2.62 110 190 0.30 0.20 0.28 0.67 61 65 68 8.5 0.68 0.66 Example 8 B 2.22 110 190 0.30 0.20 0.28 0.67 61 65 68 7.9 0.65 0.61 Comparative Example 1 A 2.62 100 175 0.35 0.27 0.32 0.77 55 68 68 7.9 0.66 0.55 Comparative Example 2 A 2.62 100 175 0.25 0.20 0.23 0.80 61 65 68 10.1 0.66 0.68 Comparative Example 3 A 2.62 100 175 0.35 0.20 0.32 0.57 60 50 50 7.5 0.68 0.55 Comparative Example 4 A 2.62 100 175 0.35 0.20 0.32 0.57 60 60 45 7.5 0.68 0.50 Comparative Example 5 A 2.62 120 150 0.30 0.20 0.28 0.67 55 60 60 9.5 0.61 0.55 Comparative Example 6 C 2.15 100 175 0.38 0.15 0.35 0.39 60 70 72 8.1 0.60 0.55 Comparative Example 7 C 2.15 100 190 0.30 0.20 0.28 0.67 61 65 68 8.9 0.59 0.53 Comparative Example 8 A 2.62 100 175 0.44 0.20 0.41 0.45 61 65 68 Poor tracking 0.68

According to the present invention, by forming the pregrooves of the R area and the prepits of the ROM area in the shape defined by the present invention, both the R area and the ROM area satisfy the DVD standard and exhibit good recording / reproducing characteristics. The prepit and pregroove can be collectively formed from the sputter disc by injection molding or the like, so that mass production of such a medium becomes possible.

Claims (8)

A recording layer comprising an organic dye capable of absorbing laser light directly or via another layer on a transparent support substrate having pregrooves and prepits, and an optical recording medium having a metal reflecting layer, wherein the organic dye is reproduced. Refractive index nk at wavelength λ _{2 is} at least 2.2; For the depth of pre-grooves and pre-pits on the substrate in the playback wavelength λ ₂ λ _4/4 or more and; Again, the following formula: 0.25r ≦ wg ≦ 0.38r; 0.25 ≦ wp / wg ≦ 0.75; θgr ≦ θpr; And θpr ≤θpt [Wherein r is the diameter of the recording laser beam represented by λ ₁ / NA, where λ ₁ is the recording wavelength [µm] and NA is the numerical aperture of the objective lens); wg [μm] is the half width of the pregroove and [theta] gr is the cross-sectional inclination angle of the pregroove in the substrate radius direction; wp [μm] is a half width in the substrate radial direction of the prepit, θpr is the cross-sectional inclination angle of the prepit in the substrate radius direction, and θpt is the cross-sectional inclination angle in the tangent direction of the prepit. Optical record carrier. 2. The recordable optical recording medium according to claim 1, wherein a pregroove and a prepit formed on said substrate satisfy a relationship such that? Gr < 3. The recordable optical recording medium according to claim 1 or 2, wherein the pregroove and the prepit have the same depth. The recordable type according to any one of claims 1 to 3, wherein the recording layer containing the organic pigment is formed on the prepit or the pregroove with a film thickness in the range of 50 m to 150 nm. Optical record carrier. 5. The recordable optical recording medium according to any one of claims 1 to 4, wherein the dye contained in the recording layer is an organic dye containing at least one pyrrole unit or a metal complex thereof. 6. The dye according to claim 5, wherein the dye contained in the recording layer is represented by the following formula (1): (Wherein, R1 to R13 are each independently a hydrogen atom, a halogen atom, C ₁ to substituted or unsubstituted alkyl group of C _12, C ₁ to alkoxy substituted or unsubstituted of C ₁₂ group or a C ₆ to C ₂₀ A substituted or unsubstituted aryl group; M is a pyrromethene-metal complex represented by). 7. The recordable optical recording medium according to any one of claims 1 to 6, wherein lambda ₁ is 0.63 µm to 0.66 µm, and NA is 0.60 ± 0.1. 8. A recordable optical recording medium according to any one of claims 1 to 7, which has a structure in which a recording layer, a reflective layer, an adhesive layer via a direct or other layer, and another substrate are laminated on a transparent substrate. .